1. Field of the Invention
The present invention relates to a pressure-sensitive adhesive composition, a conductive film, a touch panel and a pressure-sensitive adhesive film.
2. Discussion of Related Art
A touch panel is called a touch screen and applied to various data processing terminals such as a mobile communication terminal or ATM, or displays such as a TV or monitor.
For such a touch panel, a conductive film in which a conductive layer is formed on one or both surfaces of a substrate by depositing a conductor such as indium tin oxide (ITO) may be used as a basic unit part.
In the manufacture of the touch panel, a pressure-sensitive adhesive may be used to attach the conductive film to an adherent, or form a stacked structure by stacking a conductive film. Such a pressure-sensitive adhesive is maintained transparent under severe conditions such as high temperature, high temperature and humidity, or serious change in temperature or humidity, and requires physical properties which do not induce lift-off, peeling and curling.
Meanwhile, as the substrate of the conductive film, a plastic substrate may be used. However, the plastic substrate induces an out-gassing phenomenon in which moisture present therein, solvent or other additives in the plastic substrate are emitted in a gas form under a heating condition. Since the emitted gas creates bubbles and thus reduces visibility, when a pressure-sensitive adhesive is in contact with the plastic substrate, the generation of bubbles from the substrate should be prevented.
In addition, when the pressure-sensitive adhesive is directly adhered to the conductive layer of the conductive film, the pressure-sensitive adhesive layer serves to prevent resistance change in the conductive layer even when being used under severe conditions, and ensure stable drive for a long time.